Jaffueliobryum Thériot, 1928.

Two genera, Jaffueliobryum and Coscinodon, have been removed from Grimmia on the basis of the very distinctive calyptra: campanulate, plicate, fringed basally. The uninitiated person viewing that feature might even think of the distantly related genus, Orthotrichum. Coscinodon has exserted capsules; Jaffueliobryum has immersed capsules. Jaffueliobryum is a genus of mosses occupying rocks in our southeastern deserts. One is alerted in such areas to think of Jaffueliobryum when one sees an ashy brown or tan moss with very long and decurrent hyaline awns. In the field, our two species of Jaffueliobryum approach Crossidium because of the dense and erect awns on the dry plant.
see key to Grimmia Etc.

Key to Jaffueliobryum

Species included here are in Grimmiaceae:
Jaffueliobryum raui (Austin) Thériot
Jaffueliobryum wrightii Sullivant in Sullivant & Lesquereux

A. Leaves deeply concave without a semblance of a keel; hyaline awns mostly more than 1.5 times as long as the green portion of the leaf .....Jaffueliobryum raui
A. Leaves somewhat keeled distally; hyaline awn similar in length to the rest of the leaf .....Jaffueliobryum wrightii